نشریه گیاه پزشکی کاربردی
سال پنجم شماره 3 (پیاپی 19، آذر 1395)

Based on the recent results on the efficacy of Bion elicitor in increasing quince (Cydonia oblanga) resistance to fire blight caused by Erwinia amylovora bacterium, the biochemical basis of this induced defense was studied for the first time. The experiment was conducted on quince cv. Isfahan seedlings grafted on quince rootstocks under orchard condition.  In early spring, three-years-old young plants were sprayed twice with Bion (400 mg/l) in 4-days intervals and four days after the last spray, young leaves were collected for enzymes extraction and quantification. Also, phytotoxic effects of Bion were studied throughout the time course of the study in orchard. Based on the results, Bion did not induce any phytotoxicity effects on quince. Bion treatment increased polyphenol oxidase and peroxidase activities but did not affect on catalase activity. It is concluded that elevation of oxidative enzymes are a part of biochemical mechanism of Bion-mediated defense in quince but catalase enzyme activity, which dismutase reactive oxygen species, does not change.

The most important plant diseases of greenhouse plants is damping off by Phytophthora sp., the disease caused the most damage to these plants. The disease is distributed in the most parts of Iran, and it causes plant losses in about 25%. This disease is affected by environmental stresses. However, the management of these environmental factors, such as nutrition, salinity and acidity of soil could have an effective role on reducing disease. In this research, it was studied the effect of growth medium acidity on pathogen growth inhibition and the effect of some nutrients associated with the composition of changing of acidity, too. The results showed the effects of acidity on pathogen growth had significant difference between different treatments. KOH and HNO3had the highest (64.58%) and the lowest (26.25%) inhibitory effect on the pathogen growth, respectively. the results of the effect of nutrient solutions test showed that adding nutrient solution reduced the percent of damping off significantly compared to control in both Negin and Sina varieties. KNO3 had the highest reduction of damping off in both varieties of cucumber. K2SO4and KCl had most effective after potassium nitrate, and NH4NO3 showed the least effect. Based on the findings of the current study, it seems that improving plant nutrition could be a good way to reduce cucumber damping due to P. drechsleri.

Laelapidae is a large and cosmopolitan family comprises a multitude of morphologically and behaviorally diverse mites that are free-living predators that inhabit soil-litter habitats or associated with arthropods, mammals, or birds. This study is based on survey on soil inhabiting Laelapidae that was carried in 2015 from different habitats of Shahrood region. Soils and litter were collected then transferred to laboratory and put in Berlese-Tullgren funnel. Mites were extracted using it. Specimens were preserved in 75% ethanol and cleared in Lactic acid. Mites were then directly mounted into Faure medium on microscopic slides. Figures were capture and measurements were calculated using a CH2 Olympus microscope. In this study, 19 species belonging 10 genera and three subfamilies were collected and identified, all species considered as new records for the mite’s fauna of Semnan Province. Identified species are as follows:Subfamily Hypoaspidinae: Cosmolaelaps rectangularis (Sheals, 1926); Cosmolaelaps vacua (Michael, 1891); Cosmolaelaps lutegiensis (Shcherbak, 1971); Gaeolaelaps aculieifer (Canestrini, 1884); Gaeolaelaps angusta (Karg, 1965); Gaeolaelaps kargi (Costa, 1968); Gaeolaelaps nolli (Karg, 1962); Gaeolaelaps queenslandicus (Womersley, 1956); Euandrolaelaps karaawaiewi (Berlese 1903); Euandrolaelaps sardoa (Berles, 1911); Pseudoparasitus dentatus (Halbert, 1920); Pseudoparasitus hajiganbari Kazemi, 2014; Ololaelaps gamagarensis (Jordaan & Loots, 1987); Subfamily Melittiphidinae: Laelaspis pennatus (Joharchi & Halliday, 2012); Laelaspis dariusi Joharchi & Jalaeian, 2012; Laelaspisella berlesi; Joharchi, 2016 Gymnolaelaps myrmophilus (Michael, 1891);. Subfamily Laelapinae: Haemolaelaps shealsi (Costa, 1968); Haemolaelaps casalis (Berlese, 1887).

With about 600 species the Sciomyzidae or snail-killing flies are one of the most important families of Diptera. Larvae feeding mostly as predators or parasitioids on terrestrial and freshwater mollusks,and are considerable economic importance because of their pest status in agriculture. They are also intermediate hosts for a number of serious parasitic diseases of man-schistosomes and liver flukes. During studies on snail-killing flies fauna in Mazandaran Province (Iran) in 2008–2015, 10 species of 8 genera are found to occur in this region. TetanocerapunctifronsRondani, 1868is recorded for the first time for Iranian fauna.

This study aims to identify factors important pathogenic fungi in the roots, crown and base irrigated wheat in Western Azerbaijan Province in 1393 was carried out. For this purpose, wheat fields in different regions of Urmia, Naghadeh, Mahabad, Miandoab, Piranshahr, Oshnavieh, Khoy, Salmas and Qarah Zia od Din visited and from fields with symptoms of growth retardation accompanied by discoloration and decay in root, crown and base samples were taken. Pieces of 1 cm in length from the root, crown, and base were grown on acidic PDA media. Separation and purification steps of fungi were performed on WA, PDA, CMA, SNA, PCA and NM culture media. Pathogenicity test on the wheat seedling of pioneer cultivar using wheat grains and placement of mushroom blocks in the vicinity of plant organs under greenhouse conditions was carried out. Based on morphological characteristics including color and colony growth, Shape and dimensions of conidia, and conidia producing cells identified using valid keys. In this study, samples were taken from 56 farms and 81 fungal isolates belonging to the genus Fusarium, Bipolaris, Rhizoctonia and Pythium were isolated and identified. In this study, species, F. culmorum, F. avenaceum, F. graminearum, F. acuminatum and B. sorokiniana as important factors in irrigated wheat fields to nominate dumped into decay. Most of the distribution range of the genus Fusarium respectively.

The confused flour beetle, Tribolium confusum Jacquelin du Val, feeds on starchy material like flour, bran, and groats. These insects not only add significant losses to the product while feeding, but also due to the rapid population growth, the crop is infected with its feces and larval shells, and its quality is greatly reduced. Recently, many studies have been done on the application of plant essential oils or their components as a safe alternative to commonly used fumigant toxins. In this research, toxicity of three plant essential oils including Rosemary, White Pepper and Walnut leaves were investigated in three concentrations of 10, 30 and 50 μl and was compared to Rosemary extract. All experiments were carried out in laboratory conditions under temperature 27 ± 1°C, with 30 ± 5% RH and a photoperiod of 14h. The results showed that using Rosemary extract did not control T. confusum which had no significant difference with control. The essential oils of Walnut leaf, Rosemary and White Pepper made a significant difference in the mortality of the adults of the confused flour beetle. With increasing concentration, the mortality rate of T. confusum adults increased in all essential oils and all of them had a significant difference. The most percentage of mortality was observed at 50 μl concentration in Pepper essential oil. The optimum conditions for using essential oils were also investigated. So that the most pest mortality would be obtained by using 50 μl concentrations of White Pepper and Rosemary essential oils, causing 100% and 60% mortality of T. confusum, respectively.